Does a creature with menace need to be blocked by exactly two creatures or at least two?

Menace means that the creature cannot be blocked by fewer than two creatures. It sets a floor of two blockers, not an exact requirement. If the defending player has three or more eligible creatures available, they may assign all of them to block the menace creature if they wish.

This is spelled out in CR 702.111b: 'A creature with menace can't be blocked except by two or more creatures.' The word 'except' establishes a minimum threshold of two, not a fixed number. The defending player chooses how many creatures to assign as blockers, as long as that number is at least two.

Normal blocking rules still apply on top of menace. Each potential blocker must still be able to legally block the attacker (e.g., flying creatures can't be blocked by non-reach, non-flying creatures), and each blocker can only block one creature unless it has a special ability like 'can block an additional creature.'

Concrete example: Your opponent attacks with a 4/4 that has menace. You control a 1/1, a 2/2, and a 3/3, all with no special restrictions. You may block with exactly two of them (say the 2/2 and 3/3), or you may block with all three. You cannot block with only the 3/3 alone — that would be illegal because of menace.

Because combat damage is then assigned across all declared blockers, using more than two blockers can sometimes be strategically useful to spread the damage and save your creatures, depending on how the attacker assigns its damage.